Scintigraphic evaluation of colonic transit in children with constipation using 67-Ga citrate

Objectives The scintigraphic evaluation of colonic motility is usually performed with 99-mTc or 111-In tracers. Few studies used 68-Ga-citrate as radiotracer that is not absorbed from the bowel. The aim of this study is to assess the colonic transit in children and teenagers with chronic constipation.

Methods Twenty patients from 1,5 to 16 years old were included (mean age= 6,9 years). Chronic constipation etiologies were: congenital mega colon in 6; surgical treatment in 5 (imperforate anus 2, hip dysplasia 1, sacrum teratoma 1 and par spinal neuroblastoma 1); idiopathic chronic constipation in 5; sacral myelomeningocele in 3 and one intestinal duplication. Static images on the anterior projection of the abdomen were performed 1 , 6, 24, 48, 72 hours after the radiotracer oral administration. Doses were 370 MBq of 67Ga-citrate. The images were visually analyzed and classified by the observers as normal, diffuse slow transit, right slow transit and left slow transit. Patient dosimetric estimation was performed using the MIRD augurem (1).

Results There were 4 cases of diffuse slow transit that responded well to the clinical treatment, 3 of them being chronic idiopathic constipation. From 5 patients with right slow transit, 4 were submitted to appendicostomy (Malone surgery) with good results. There were 11 cases of left slow transit (ten at the recto-sigmoid level). Five of the 6 patients with congenital mega colon had left slow transit. Patient doses estimation were 1,9 mSv to the whole body, 1,8 mSv to the ovaries and 1,4 mSv to the testicular.

Conclusions This method is simple, secure, non invasive and provides helpful functional information regarding chronic constipation in children and teenagers. Reference- 1-MIRD/dose report n2 - Summary of current radiation dose estimates to humans from 66Ga-, 68Ga-, and 72Ga-citrate. J Nucl Med,1973;14(10):755-756.